Madrid goalkeeper Casillas breaks left thumb

Thursday 24 January 2013 15.38 CET

Real Madrid CF goalkeeper Iker Casillas faces a race to be fit for his side's UEFA Champions League round of 16 opener against Manchester United FC on 13 February after breaking his left thumb against Valencia CF.

Casillas was substituted in the 16th minute of Wednesday's Copa del Rey quarter-final second leg at Mestalla, where a 1-1 draw proved enough for a 3-1 aggregate win. Tests have shown that the Spanish international fractured a metacarpal bone in his left hand and, although the exact prognosis is yet to be determined, it is thought the 31-year-old could be out for six weeks.

"There was a loose ball and Álvaro [Arbeloa] went to clear it but kicked my hand," said Casillas, who was replaced by Antonio Adán. "As soon as he connected I knew it wasn't good. When I tried to make a fist it hurt. [On first examination] the doctor noticed something he didn't like."

Madrid host Manchester United in three weeks' time before the return match at Old Trafford on 5 March.